From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 788A4C433E0 for ; Sun, 3 Jan 2021 06:54:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 323F22078D for ; Sun, 3 Jan 2021 06:54:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725874AbhACGx4 (ORCPT ); Sun, 3 Jan 2021 01:53:56 -0500 Received: from mout.gmx.net ([212.227.15.18]:49759 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725294AbhACGxz (ORCPT ); Sun, 3 Jan 2021 01:53:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1609656738; bh=V71nJV1yj67Vrv0GU3OhZGBwQZbN8EIOLn8tT/ukABs=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=MeLUinmuDXOdPZz+zyJTJF3FFporeKp92JvGuZK2uX6UGUnX8lqlsfED1oQu0O5O3 4Sfz3mSYKivDcXi7z/rVrsJCZ2QOJi6WEgefIKacK4I2kGMJAjk21KOGFcbAqFeY/A xNMeHWUDRg2ZzSkr+dBiXi585ZxMQIvPpg+3YlcQ= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1M5QJD-1kwmay2AKL-001ODJ; Sun, 03 Jan 2021 07:52:18 +0100 Subject: Re: [PATCH] btrfs: fix NULL pointer dereference in extent_io_tree_panic() To: Su Yue , linux-btrfs@vger.kernel.org References: <20210103050156.2866-1-l@damenly.su> From: Qu Wenruo Message-ID: <5a1fa648-15b2-1729-b697-dd4a3874cad7@gmx.com> Date: Sun, 3 Jan 2021 14:52:10 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210103050156.2866-1-l@damenly.su> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:JR4RQYWuS68rwTwUc25XH8q8ZcwZj/Dh5MZrsurzAfsNIqUFQYi 5ZS21vkiR6UDW+RF+I9KiZ4lW5jj0J9xo7h6YiNhuM1Su5oas2nTgYVirRm3dmgNh+7Tlgy ztlaj9R6TDq4BGDaXWA2D+zj9+DKFB+CcQqivFVpwL1rtypW6Ifs8t/rQnx7qa9VL/qs14K rpJW5PwKnPWMWYMz6pvhg== X-UI-Out-Filterresults: notjunk:1;V03:K0:+Yao2uqkJcU=:wCT/cZhYRo041u5qvxRR7h gfXoXkoo0BRGMP+UZaeQ2161Y+yB9z3/HvlTUdH8kY3ryhnI4IaclE3QMJ2iKWsyCAddcDoKS pGsyjqOpAbxA/RVV+CdDs98oDbdUESEa1vVh3aZviQtySrFiaho+wgH+TX946l5vlKeLGuyu5 MB5J6X8O7GrIMjW+KL5eZsaR38RA/cNy9ZvfUB384uzD1qQAuXJnzt4JnhO1c+gL4z/UR+3I6 1+4X7q0GPRInSVaPwC3gIBKM5Yzcjlb+couYyImHCeyVrl+T68htEuLTlEirkUGo+t4k/RjIt lr0vCMyc5EZLV5aCDQkp2qdjX4cAQUvN0nvRJp1HTAIuOFyf9MB4stY1GsMSgiiKTpa78O/px Mvta7K0ooeyqu1lAEkAy7mx+7MEwMC00j42FaDJhjx+8mhk83pHhJ683qhRaL7F6P6SMV/UYh QpaH9p/tNqWfhzZHMDhzDqzAyNMlm89pppgmHhzrRzkLMGhjtzOh9oK2qU87FS+8OMmu2okRT qd5uCpnLZ6C89jwN1/Hlt6LWuJhpMu/CGvUWl56hV9u6h7ugGAUjmY4+aO3/AydBTAuEWvZuC ZCJERP56bGOltBR7ZNZ6q43M0r+mW3KcoAsOBpXnI6dVVPOPcnyrSLOjjpB6pKXlncH4s4UPJ erJChbLd2pGWJz8FiubM10JldQP2Dc+625IFQBTBq0dd9ofrVfbbBtgc0DlGoZPTTGwv98kQP Y4OeARlYBS2vO5q1k4ZZywp+fKAAyvU3i2ES5FPw+pvE4T0IpduByswCYfH+kkRyUdg8JWGH+ Zo6B+5DCUJuIopoH1mErXIdO6mpyKCH+p9i6ofOZ1u/n4PXq5V5V6I4Gu4N9QP6IlybGT9fPi AAtwRhsdiT6HKY9VRFEA== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2021/1/3 =E4=B8=8B=E5=8D=881:01, Su Yue wrote: > while mounting the poc image user-provided, kernel panics due to the > NULL deference of @tree->inode. > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > [ 109.663024] BTRFS error: found node 12582912 29360127 on insert of 37= 748736 29360127 > [ 109.663032] BUG: kernel NULL pointer dereference, address: 0000000000= 000028 > [ 109.664494] #PF: supervisor read access in kernel mode > [ 109.665543] #PF: error_code(0x0000) - not-present page > [ 109.666598] PGD 0 P4D 0 > [ 109.667119] Oops: 0000 [#1] PREEMPT SMP NOPTI > [ 109.668015] CPU: 14 PID: 641 Comm: mount Tainted: G W O = 5.11.0-rc1-custom #45 > [ 109.669707] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BI= OS ArchLinux 1.14.0-1 04/01/2014 > [ 109.671607] RIP: 0010:extent_io_tree_panic.isra.0+0x6/0x30 [btrfs] > [ 109.672911] Code: 89 fe 48 c7 c7 20 0e aa c0 48 89 e5 e8 3a b9 ee dd = 0f 0b be c0 13 00 00 48 c7 c7 48 0e aa c0 e8 d1 ff ff ff 0f 1f 44 00 00 55= <48> 8b 47 28 89 f1 49 c7 c0 70 0e aa c0 ba a9 02 00 00 48 c7 c6 00 > [ 109.676740] RSP: 0018:ffffb76c814fb948 EFLAGS: 00010282 > [ 109.677808] RAX: 00000000ffffffef RBX: 0000000001bfffff RCX: 00000000= 00000000 > [ 109.679271] RDX: ffffb76c814fb99c RSI: 00000000ffffffef RDI: 00000000= 00000000 > [ 109.680722] RBP: ffffb76c814fb9e0 R08: 0000000000000001 R09: 00000000= 00000001 > [ 109.682179] R10: ffffb76c814fb658 R11: 0000000000000000 R12: ffff9aca= c353e500 > [ 109.683629] R13: ffff9acac89a8228 R14: ffff9acac353e8c0 R15: 00000000= 02400000 > [ 109.685092] FS: 00007fb1f7dc3580(0000) GS:ffff9acb48c00000(0000) knl= GS:0000000000000000 > [ 109.686749] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 109.687927] CR2: 0000000000000028 CR3: 0000000103982000 CR4: 00000000= 00750ee0 > [ 109.689380] PKRU: 55555554 > [ 109.689935] Call Trace: > [ 109.690438] ? set_extent_bit.cold+0x30/0x98 [btrfs] > [ 109.718452] set_extent_bits_nowait+0x1d/0x20 [btrfs] > [ 109.741357] add_extent_mapping+0x1e0/0x2f0 [btrs] > [ 109.761474] read_one_chunk+0x33c/0x420 [btrfs] > [ 109.781087] btrfs_read_chunk_tree+0x6a4/0x870 [btrfs] > [ 109.800486] ? kvm_sched_clock_read+0x18/0x40 > [ 109.819669] open_ctree+0xb32/0x1734 [btrfs] > [ 109.838794] ? bdi_register_va+0x1b/0x20 > [ 109.857812] ? super_setup_bdi_name+0x79/0xd0 > [ 109.876880] btrfs_mount_root.cold+0x12/0xeb [btrfs] > [ 109.895860] ? __kmalloc_track_caller+0x217/0x3b0 > [ 109.914731] legacy_get_tree+0x34/0x60 > [ 109.933041] vfs_get_tree+0x2d/0xc0 > [ 109.950757] vfs_kern_mount.part.0+0x78/0xc0 > [ 109.968262] vfs_kern_mount+0x13/0x20 > [ 109.984976] btrfs_mount+0x11f/0x3c0 [btrfs] > [ 110.001475] ? kfree+0x5ff/0x670 > [ 110.017410] ? __kmalloc_track_caller+0x217/0x3b0 > [ 110.033439] legacy_get_tree+0x34/0x60 > [ 110.049000] vfs_get_tree+0x2d/0xc0 > [ 110.064604] path_mount+0x48c/0xd30 > [ 110.080199] __x64_sys_mount+0x108/0x140 > [ 110.095918] do_syscall_64+0x38/0x50 > [ 110.111366] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [ 110.126869] RIP: 0033:0x7fb1f7f42f6e > [ 110.141818] Code: 48 8b 0d 05 0f 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 = 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05= <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d d2 0e 0c 00 f7 d8 64 89 01 48 > [ 110.188250] RSP: 002b:00007fff152c68a8 EFLAGS: 00000246 ORIG_RAX: 000= 00000000000a5 > [ 110.220331] RAX: ffffffffffffffda RBX: 00007fb1f8067264 RCX: 00007fb1= f7f42f6e > [ 110.237474] RDX: 00005608be216360 RSI: 00005608be208690 RDI: 00005608= be20f6c0 > [ 110.254718] RBP: 00005608be208440 R08: 0000000000000000 R09: 00000000= 00000001 > [ 110.272042] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000= 00000000 > [ 110.288955] R13: 00005608be20f6c0 R14: 00005608be216360 R15: 00005608= be208440 > [ 110.305969] Modules linked in: > [ 110.458051] CR2: 0000000000000028 > [ 110.478548] ---[ end trace 3499c8e7baa57952 ]--- > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > The image has a device extent whose end(29360127) is less than the start > (37748736). btrfs did warn but continued to insert the invalid sate > to device::alloc_state tree. Then tree_insert() returned -EEXIST > because of the duplicate end. extent_io_tree_panic() was to be called. > However, the @tree->inode is NULL in extent_io_tree_panic() and it > should be NULL here because that device::alloc_state io tree's member > @private is NULL by design. > > Just pass @tree->fs_info as parameter to extent_io_tree_panic() > directly. Let it panic as expected at least. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=3D208929 > Fixes: 05912a3c04eb ("btrfs: drop extent_io_ops::tree_fs_info callback") > Signed-off-by: Su Yue This looks OK as a simple fix. Reviewed-by: Qu Wenruo > > --- > I don't know why insert_state() code only warns about the invalid state > and extent io operations are used in so many places. So just send the > simple patch. Although I'd prefer a more comprehensive fix, by doing overflow check on device extent item to reject such tree block. Thanks, Qu > --- > fs/btrfs/extent_io.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 6e3b72e63e42..c9cee458e001 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -676,9 +676,7 @@ alloc_extent_state_atomic(struct extent_state *preal= loc) > > static void extent_io_tree_panic(struct extent_io_tree *tree, int err) > { > - struct inode *inode =3D tree->private_data; > - > - btrfs_panic(btrfs_sb(inode->i_sb), err, > + btrfs_panic(tree->fs_info, err, > "locking error: extent tree was modified by another thread while lock= ed"); > } > >